The present invention relates to a searchlight or headlight for motor vehicles.
More particularly the invention relates to a bulb assembly for a vehicle headlight.
Vehicle headlights with sealing arrangements for sealing a bulb against a reflector of the headlight have been disclosed, for example in Applicant's U.S. Pat. Nos. 3,809,880 and 3,689,103. Often a sealing O-ring is inserted into an annular groove provided in the outer peripheral surface of the socket of the bulb. The width of the annular groove, or its size in the axial direction of the bulb is insignificantly greater than the diameter of the O-ring positioned in the groove. When the bulb is inserted into the lamp holder provided on the reflector of the headlight and also when the bulb is pulled out from the lamp holder the O-ring shifts along the inner surface of the lamp holder; a plug-in force or a pulling-out force required for these actions is about 40 Newton.
The pulling-out of the bulb from the lamp holder usually takes place in a jerky manner so that a danger of injury due to a narrow space in a pulling-out region behind the headlight is not excluded. This injury danger becomes greater the longer is the bulb in use because the O-ring can bake together with the inner surface of the lamp holder and particularly with the base of the groove, and the pulling-out force must be then many times greater.